William h



,PETER PHOTO-LITHOGRAPHER, WASHINGTON. D. C.

@anni iiilre.

WILLIAM ROBERTS, OF MAIIOH OHUN K, PENNSYLVANIA.

Letters Patm1.tNo.-100,449, dated March 1,*1870.

DEVICE FOR SEOURING UNIFORM MOTION IN PUMPING-ENGINES- The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern.: Bc it known that I',W1LLIA.\1 H.r RoBnRTs, of Manch Ohunk,'in the county oi' Carbon, and State of Pennsylvania, have invented a new'and Improved Steam Pumping-Engine; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the accompanying drawings making a part of this specification, in which- Figure l is a horizontal axial section; and

Figure 2 is a sectional elevation of a modification of the same.

This invention has for its object to secure uniformity of motion in the plunger of a steam-pump throughout the stroke.

` Theinvention is au improvement over that patented by meMarch 30, 1869, and consists in a. regulatingcylinderlor water-cushion connected with the valve apparat-us of theengine, for the purpose specified. In the drawingsaI a are two smallcylinders, placed end to end upon the main pump-cylinder, a pipe, al, provided with a choke-valve, a", connecting their contiguous ends.

IVithin each cylinder is a plunger, l), of a diameter but little less than that ot' the. cylinder, and of a length somewhat greater. y

'lo the outer vend ol' cach plunger' is secured a crossbar, b", which cross-bars areuniled by` stay-'rods If,

one on each side of the cylinders.

One of they cross-bars is directly connected with the valve-mechanism .of the engine, and the apparatus constrains the latter to more steadily, forcing the waiter `from one cylinder to the other through the pipe al,

at one stroke, and back again on the return stroke.

The choke-valve regulates the speed at which the i plungers may move.

My patent of March 30, 1869, as well as that of R.

Allison, dated September 29, 1868, both describe an invention consisting of a single cylinder, filled with Aliquid, which is alternately forced by the action of the piston from one vend of the cylinder to the other through an external pipe, whose extremities open out of the cylinder near its ends. The points wherein my present invention is an improvement upon these are:

First, it enables me to place the regulating apparatus in an inclined or vertical position, as is frequently necessary, without subjecting it to the disadvantage which attends the other form when similarly placed, that is, the unequal motion ofthe piston in the down and up strokes, which defeats the very object of the apparatus, and which is remedied by employing two pistons in separate cylinders, the lower one being of less diameter than the upper, so thatfon the down stroke, the dow of water is hindered by the smallness of the lower cylinder, and on the up stroke the resistance is diminished by the smallness of the lower piston.

Second, if there arises any imperfection in the packing, it, heilig in the outer ends of the cylinder, and easily accessible, may be readily repaired, whereas the packing of the piston within the cylinder is not so easily got at, nor s readily detected.

Added to the foregoing advantages is the extreme simplicity of the apparatus.

Having thus described my invention,

What I claim as new, and desire to secure by Let-- The combination of the cylinders a a. Awith the plungers b b, connecting-rod b', and connecting-pipe al, in the manner and for the purpose described.

To the above specification of my improvement I have set my hand this 1st Aday of December, A. D.v 1869.

y W. H. ROBERTS. Witnesses:

CHAs. A. PETTIT,

SoLoN C. KnMoN. 

